1. Field of the Invention
This invention relates generally to electrical wiring and conduit and, more specifically, to a Non-metallic Elbow Conduit Transition Fitting.
2. Description of Related Art
Commercial building construction generally involves the use of metal framing and concrete flooring. This approach is used due to the superior long-term durability and fire safety that these types of structures provide. The construction of these buildings is essentially a process of erecting the building floor-by-floor using metal framing members and then pouring a concrete floor as each level is completed.
As a result of this specialized approach, there are many utilities installation approaches that are radically different in the commercial construction environment as compared to the residential construction environment. A particular distinction exists between residential electrical systems and commercial electrical systems. While in a residential system, electrical wiring passes from floor-to-floor many times through wall studs, floor joists and ceiling rafters, when in the commercial building the concrete flooring prevents this approach.
When electrical wiring passes from floor-to-floor in a commercial building, it generally rises vertically through a penetration into the concrete floor of the floor above. The wiring then is rerouted to the perimeter of the floor so that it might gain access to exterior walls and/or junction boxes located elsewhere in the building. This approach is used because typically electrical wiring comes from the outer walls towards the center rather than coming up through the floor for use in the center of the floor. This permits the greatest flexibility in moving nonstructural walls within the commercial space.
In the past when transitioning from a vertical conduit riser into a conduit lateral housed within a concrete floor, there has been no off-the-shelf product available. The problem is that the vertical conduit is typically snap-on or threaded metallic conduit in order to comply with typical electrical building codes, when the conduit passes through concrete it is generally of a non-metallic type.
In order to interconnect the non-metallic horizontal lateral and the metallic vertical riser, the electrician will typically be required to modify some existing metallic conduit connector because there previously has been none suited for this particular application. The typical off-the-shelf elbow does not provide the non-metallic solvent or slip-fitting at one end while providing the threaded connection for interfacing with metallic conduit at the other end. Furthermore, the bend radius of a typical conduit elbow tends to be greater than is acceptable for encasing in a thin concrete floor.
What is needed then is a non-metallic low-clearance elbow that provides a transition from metallic conduit to non-metallic conduit without need for further modification.